Generally, this disclosure relates to respirator assemblies that are worn on a user's head to provide breathable air for the user.
Respirators are well known and have many uses. For example, certain types of respirators may be used to aid the users' breathing in a contaminated atmosphere, such as a smoke filled atmosphere, a fire or a dust laden atmosphere, a mine, a toxic atmosphere, or a laboratory. Respirators may also be worn where it is desired to protect the user from contaminating the surrounding atmosphere, such as when working in a clean room used to manufacture silicone chips.
Some respirators include a hard shell portion that is intended to provide at least some protection against impacts, when working in a dangerous environment or when the user is at risk of being struck by falling or thrown debris such as in a mine, an industrial setting, or on a construction site. Another type of respirator employs a soft shell when head protection from impact is not believed to be required such as, for example, when working in a laboratory or a clean room.
A respirator hood is usually made of a soft, flexible material suitable for the environment in which the hood is to be worn, and an apron or skirt may be provided at a lower end of the hood to extend over the shoulder region of the user. Hoods of this type are sometimes used with a bodysuit to isolate the user from the environment in which the user is working. The apron or skirt often serves as an interface with the bodysuit to shield the user from ambient atmospheric conditions. A respirator head cover does not cover a user's entire head, but typically only extends above the ears of the user and down about the chin of the user in front of the user's ears. The hood or head cover has a transparent region at the front, commonly referred to as a visor, through which the user can see. The visor may be an integral part of the hood or head cover or it may be detachable so that it can be removed and replaced if damaged.
A respirator hard shell portion is usually made from a hard, inflexible material suitable for the environment in which the respirator is to be worn. For example, such materials may include metallic materials, such as steel, or hard polymers. A respirator hard shell portion typically will extend at least over the top of the user's head, and may have a brim around all sides thereof, or a bill extending forwardly therefrom, thereby providing additional protection over the user's facial area. In addition, such a respirator may also include protective sides extending downwardly from along the rear and sides of the user's head. Such sides may be formed from an inflexible material or may be formed from a flexible material. A respirator assembly having a hard shell portion may also include a visor that permits the user to see outside of the respirator. The visor may be transparent. However, in some instance, such as for welding, the visor may be tinted or it may include a filter or shutter, such as an auto darkening fitter (ADF). The visor may be an integral part of the respirator assembly or it may be detachable so that is can be removed and replaced if damaged.
A respirator shell is intended to provide a zone of breathable air space for a user. As such, the shell is also typically sealed about the user's head and/or neck area. At least one air supply provides breathable air to the interior of the respirator. The air supply pipe may be connected to a remote air source separate from the user, but for many applications, the air supply pipe is connected to a portable air source carried by the user, for example, in a backpack or on a belt. In one form, a portable air supply comprises a turbo unit, including a fan driven by a motor powered by a battery and a filter. The portable air supply is intended to provide a breathable air supply to the user for a predetermined period of time.
Air may be distributed within a respirator from one or more outlets. However, the user of a typical respirator may be unable to control the direction of air flow from the outlet(s). What one person perceives as a pleasant breeze, another person may consider to be a cold draft. In some cases a particular distribution of air flow may actually cause user discomfort, such as, for example, the drying of a user's eyes.